The present invention relates generally to improvements in photoflash photography and it relates more particularly to an improved photoflash photography apparatus in which the light output of an electronic photoflash unit is automatically adjusted in accordance with the sensitivity of the film with which the camera is loaded.
In the practice of photoflash photography many parameters must be relatively adjusted and these include the camera diaphragm aperture, the object camera distance and the amount of light emitted by the photoflash device. Hitherto, the adjustment for the film sensitivity has generally been effected by the manual adjustment of a setting member which is provided in the camera or the flash unit. In this connection, the setting member is provided on the flash unit or device in the case where a calculating dial for determining a suitable aperture value based on the camera-object distance is provided for the flash unit or the flash device has an automatic control device for controlling the time interval during which the flash is being fired. In the alternative, the setting member is provided on a camera in case the camera is provided with means for automaticallly controlling the diaphragm aperture commensurate with the camera-object distance through mechanical interconnection of a focus adjusting member and the diaphragm setting member. However, such manual setting system is unreliable in that an operator may fail to change the film sensitivity setting with changes in sensitivity of film used in the camera, resulting in defective exposure. It is accordingly clear that the conventional photoflash photography systems possess numerous drawbacks and disadvantages in that they are unreliable and inconvenient in operation, frequently highly time consuming and otherwise leave much to be desired.